In our paper, we present a new design for a single-grating tunable spatial heterodyne spectrometer (SHS). Our design simplifies the change of the center wavelength (Littrow wavelength) thus one can quickly tune the system to an arbitrary spectral range. Furthermore, we introduce a new calibration method that provides superior calibration accuracy over the generally used formulas involving small angle approximations. We also present considerations about the general usability of the SHS technique in broadband measurements and propose different strategies to improve the signal-to-noise ratio.Two errata are presented to correct two typographical errors in our paper.We present an erratum concerning the repetition rate of the fs-laser system used for the inscription of the waveguides stated in our paper [Opt. Express 28, 12011-12019 (2020)]. The Fidelity HP High Energy laser supplied by Coherent Inc. features a repetition rate of 10 MHz instead of the value of 1 MHz stated in the paper.Controlling spontaneous emission by modifying the local electromagnetic environment is of great interest for applications in optoelectronics, biosensing and energy harvesting. Although the development of devices based on one-dimensional porous silicon photonic crystals with embedded luminophores is a promising approach for applications, the efficiency of the embedded luminophores remains a key challenge because of the strong quenching of the emission due to the contact of the luminophores with the surface of porous silicon preventing the observation of interesting light-matter coupling effects. Here, we experimentally demonstrate an increase in the quantum dot (QD) spontaneous emission rate inside a porous silicon microcavity and almost an order of magnitude enhancement of QD photoluminescence intensity in the weak light-matter coupling regime. Furthermore, we have demonstrated drastic alteration of the QD spontaneous emission at the edge of the photonic band gap in porous silicon distributed Bragg reflectors and proved its dependence on the change in the density of photonic states.A specular-reflection photonic nanojet (s-PNJ) is a specific type of optical near-field subwavelength spatial localization originated from the constructive interference of direct and backward propagated optical waves focused by a transparent dielectric microparticle located near a flat reflecting mirror. https://www.selleckchem.com/products/abemaciclib.html The unique property of s-PNJ is reported for maintaining its spatial localization and high intensity when using microparticles with high refractive index contrast when a regular photonic nanojet is not formed. The physical principles of obtaining subwavelength optical focus in the specular-reflection mode of a PNJ are numerically studied and a comparative analysis of jet parameters obtained by the traditional schemes without and with reflection is carried out. Based on the s-PNJ, the physical concept of an optical tweezer integrated into the microfluidic device is proposed provided by the calculations of optical trapping forces of the trial gold nanosphere. Importantly, such an optical trap shows twice as high stability to Brownian motion of the captured nano-bead as compared to the conventional nanojet-based traps and can be relatively easy implemented.The recent emergence of digital coding metasurfaces has significantly simplified the design of functional devices and manipulated electromagnetic waves digitally. In this paper, we propose a dielectric coding metasurface with different functions, which is implemented by a metasurface with specific coding sequences. It is composed of a three-dimensional T-shaped dielectric block placed on a metal plate. Compared with traditional metal resonators, the all-dielectric metasurface has relatively low loss and the reflection amplitude maintains a high value. Here, we demonstrate five different functions of anomalous reflection, beam splitting, diffuse scattering, line focusing, and vortex beam generation achieved under normal incidence of the linearly polarized wave. Through full-wave numerical simulation, the far-field scattering patterns and near-field electric-field intensity distribution of the proposed metasurface under various reflection conditions are obtained, which is in good agreement with the theoretical prediction. It is verified that the multifunctional dielectric coding metasurface provides a new way to control the reflection of terahertz waves.In this work, a polarization-free coding metasurface is proposed to manipulate circularly polarized waves. Compared to a Pancharatnam-Berry phase metasurface, the proposed design not only allows for overcoming anti-symmetrical response characteristics between orthogonal circularly polarized states to enable achieving identical functionality under both right-handed and left-handed circularly polarized wave illuminations and avoiding polarization-conversion losses but also offers additional degree of freedom in the control of handedness. As a proof-of-concept demonstration, a polarization-free multi-bit coding metasurface is designed to realize helicity-switched holograms in the microwave region. Experimental measurements performed on a fabricated prototype reveal outstanding imaging quality with extremely high imaging efficiency above 76% for arbitrary polarizations at 10?GHz. Our proposed method expands the route in manipulating circularly polarized waves and can be applied over the whole electromagnetic spectrum for wavefront manipulation.It is beneficial to improve the resolution by a diffuser in imaging systems, because higher frequency information could be involved into the captured patterns via scattering effect. In this paper, a lensless imaging method is designed by 1-D scanning. A diffuser is placed upstream of the object, which is translated in a one-dimensional path and corresponding positions are corrected by cross-correlation. Our method requires a diffraction pattern of the object without a diffuser to speed up convergence and improve resolution. In field reconstruction, the amplitude constraint is added into the iterative phase retrieval algorithm. The high-quality complex-valued images can be obtained with ?15 patterns. As a ptychography, the proposed method only needs a 1-D device, which could simplify the experimental equipment for reducing costs and measurement time.